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The Smallest FreeBSD Kernel Config for a Guest VM

About our FreeBSD Kernel Config

This is what I use for a FreeBSD kernel configuration when FreeBSD is running on VirtualBox as a guest. There's a little more you could trim off of this kernel configuration. But, only if you knew exactly which features/hardware configuration you were going to be using.

FreeBSD Kernel Configuration for VirtualBox Guests

cpu             HAMMER
ident VBOX

options SCHED_ULE # ULE scheduler
options PREEMPTION # Enable kernel thread preemption
options INET # InterNETworking
options INET6 # IPv6 communications protocols
options IPSEC # IP (v4/v6) security
options TCP_OFFLOAD # TCP offload
options SCTP # Stream Control Transmission Protocol
options FFS # Berkeley Fast Filesystem
options SOFTUPDATES # Enable FFS soft updates support
options UFS_ACL # Support for access control lists
options UFS_DIRHASH # Improve performance on big directories
options UFS_GJOURNAL # Enable gjournal-based UFS journaling
options QUOTA # Enable disk quotas for UFS
options NFSCL # Network Filesystem Client
options NFSD # Network Filesystem Server
options NFSLOCKD # Network Lock Manager
options NFS_ROOT # NFS usable as /, requires NFSCL
options CD9660 # ISO 9660 Filesystem
options PROCFS # Process filesystem (requires PSEUDOFS)
options PSEUDOFS # Pseudo-filesystem framework
options GEOM_PART_GPT # GUID Partition Tables.
options GEOM_LABEL # Provides labelization
options COMPAT_FREEBSD32 # Compatible with i386 binaries
options SYSVSHM # SYSV-style shared memory
options SYSVMSG # SYSV-style message queues
options SYSVSEM # SYSV-style semaphores
options _KPOSIX_PRIORITY_SCHEDULING # POSIX P1003_1B real-time extensions
options PRINTF_BUFR_SIZE=128 # Prevent printf output being interspersed.
options KBD_INSTALL_CDEV # install a CDEV entry in /dev
options HWPMC_HOOKS # Necessary kernel hooks for hwpmc(4)
options AUDIT # Security event auditing
options CAPABILITY_MODE # Capsicum capability mode
options CAPABILITIES # Capsicum capabilities
options MAC # TrustedBSD MAC Framework
options INCLUDE_CONFIG_FILE # Include this file in kernel
options RACCT # Resource accounting framework
options RACCT_DEFAULT_TO_DISABLED # Set kern.racct.enable=0 by default
options RCTL # Resource limits

# Make an SMP-capable kernel by default
options SMP # Symmetric MultiProcessor Kernel

# CPU frequency control
device cpufreq

# Bus support.
device acpi
options ACPI_DMAR
device pci
options PCI_IOV # PCI SR-IOV support

# ATA controllers
device ahci # AHCI-compatible SATA controllers
device ata # Legacy ATA/SATA controllers
options ATA_STATIC_ID # Static device numbering

# ATA/SCSI peripherals
device scbus # SCSI bus (required for ATA/SCSI)
device da # Direct Access (disks)
device cd # CD
device pass # Passthrough device (direct ATA/SCSI access)
device ses # Enclosure Services (SES and SAF-TE)
#device ctl # CAM Target Layer

# atkbdc0 controls both the keyboard and the PS/2 mouse
device atkbdc # AT keyboard controller
device atkbd # AT keyboard
device psm # PS/2 mouse

device kbdmux # keyboard multiplexer

device vga # VGA video card driver
options VESA # Add support for VESA BIOS Extensions (VBE)

device splash # Splash screen and screen saver support

# syscons is the default console driver, resembling an SCO console
device sc
options SC_PIXEL_MODE # add support for the raster text mode
# vt is the new video console driver
device vt
device vt_vga
device vt_efifb

device agp # support several AGP chipsets

# PCI Ethernet NICs.
device em # Intel PRO/1000 Gigabit Ethernet Family

# Pseudo devices.
device loop # Network loopback
device random # Entropy device
device rdrand_rng # Intel Bull Mountain RNG
device ether # Ethernet support
device vlan # 802.1Q VLAN support

# The `bpf' device enables the Berkeley Packet Filter.
# Be aware of the administrative consequences of enabling this!
# Note that 'bpf' is required for DHCP.
device bpf # Berkeley packet filter

# USB support
device uhci # UHCI PCI->USB interface
device ohci # OHCI PCI->USB interface
device ehci # EHCI PCI->USB interface (USB 2.0)
device xhci # XHCI PCI->USB interface (USB 3.0)
device usb # USB Bus (required)
device ukbd # Keyboard
device umass # Disks/Mass storage - Requires scbus and da
# VirtIO support
device virtio # Generic VirtIO bus (required)
device virtio_pci # VirtIO PCI device
device vtnet # VirtIO Ethernet device
device virtio_blk # VirtIO Block device
device virtio_scsi # VirtIO SCSI device
device virtio_balloon # VirtIO Memory Balloon device

# Netmap provides direct access to TX/RX rings on supported NICs
device netmap # netmap(4) support

# The crypto framework is required by IPSEC
device crypto # Required by IPSEC

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